In a turbine, the fluid expands almost_________________?

Related Mcqs:

1. High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process ?

   A. Δ H = 0 and ΔS = 0
   B. Δ H ≠ 0 and ΔS = 0
   C. Δ H ≠ 0 and ΔS ≠ 0
   D. Δ H = 0 and ΔS ≠ 0

2. 4 kg moles of an ideal gas expands in vacuum spontaneously. The work done is_________________?

   A. 4 J
   B. ∞
   C. 0
   D. 8 J

3. The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is_________________?

   A. R loge 4
   B. R log10 4
   C. Cv log10 4
   D. Cv loge 4

4. When a gas in a vessel expands, its internal energy decreases. The process involved is________________?

   A. Reversible
   B. Irreversible
   C. Isothermal
   D. Adiabatic

5. 1m3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be ?

   A. 35 K
   B. 174 K
   C. 274 K
   D. 154 K

6. Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 kJ/kg. K) The exit condition of steam is_______________?

   A. Superheated vapour
   B. Partially condensed vapour with quality of 0.9
   C. Saturated vapour
   D. Partially condensed vapour with quality of 0.1

7. Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is_____________________?

   A. Positive
   B. Negative
   C. Zero
   D. Infinity

8. For an incompressible fluid, the _______________ is a function of both pressure as well as temperature?

   A. Internal energy
   B. Enthalpy
   C. Entropy
   D. All (A), B. & (C)

9. In an ideal refrigeration cycle, the change in internal energy of the fluid is_____________?

   A. +ve
   B. -ve
   C. 0
   D. Either of the above three; depends on the nature of refrigerant

10. In jet refrigerators, the refrigerating fluid is practically always_________________?

    A. Water
    B. Ammonia
    C. Freon
    D. Brine